#include<iostream>
#include<cstdio>
using namespace std;

int main()
{
	int n = 0;
	cin >> n;
	int sum = 0;
	for (int i = 1; i <= n; i++)
	{
		int a = 0;
		cin >> a;
		sum += a;
	}
	printf("%.2f", sum * 1.0 / n);
	
	return 0;
}
